ML Tools
Regression Metrics Calculator
Calculate MAE, MSE, RMSE, R², and MAPE from actual/predicted values.
One pair per line: actual,predicted. An optional header row is detected automatically.
RMSE
9.2195
Rows used
5
MAE
9
MSE
85
R²
0.983
MAPE
4.80%
Formulas
Formula
MAE = mean(|actual − predicted|)
MSE = mean((actual − predicted)²)
RMSE = sqrt(MSE)
R² = 1 − (Σ(actual − predicted)² / Σ(actual − mean(actual))²)
MAPE = mean(|actual − predicted| / actual) × 100Frequently asked questions
Why is MAPE sometimes undefined?
MAPE divides the error by the actual value. When any actual value is zero, that division is undefined, so this tool skips MAPE rather than silently showing a misleading number.
What does a negative R² mean?
R² can go negative when a model performs worse than simply predicting the mean of the actual values every time.